1. Field of the Invention
The present invention relates to a quick connect swivelable connector for tubular conduits.
2. Description of the Related Art
Swivelable connectors are used in many applications for connecting hoses for supplying a fluid such as water or oil, and conventionally, connectors of the threaded type are typically used. Such connectors, however, require skill and time for assembly, and thus simpler connectors are demanded.
U.S. Pat. Nos. 4,524,995 and 4,601,497, issued to Bartholomew on June 25, 1985 and July 22, 1986, respectively, disclose a quick connect swivelable connector comprising a first tubular connector member (housing), a second tubular connector member (a tubular conduit) inserted in the first tubular connector member and having an annular projection, a sealing means between the first and second tubular connector members, and a resilient retainer secured to the first tubular connector member to engage with the annular projection of the second tubular connector member. The resilient retainer preferably comprises a pair of snapping jaws. In this connector, assembly can be easily carried out by securing the resilient retainer to the first tubular connector member and then inserting the second tubular connector member in the resilient retainer and in the first tubular connector member until the annular projection of the second tubular connector member passes beyond the resilient retainer, whereby the second tubular connector member cannot be disconnected from the first tubular connector member.
It is, of course, necessary to enlarge a portion of the first tubular connector member to allow insertion of the second tubular connector member in the first tubular connector member, but the annular projection of the second tubular connector member necessitates a greater enlargement of a corresponding portion of the first tubular connector member. Therefore, preferably the annular projection is eliminated to obtain a compact connector.
From this aspect, Japanese Unexamined Utility Model Publication No. 63-17390, published on Feb. 4, 1988 and filed by the inventor for this application, discloses a swivelable connector comprising a first tubular connector member, a second tubular connector member with an end portion inserted in the first tubular connector member and an annular groove on that end portion, and a retainer for retaining the second tubular connector member in the first tubular connector member. The first tubular connector member preferably has a plurality of apertures formed adjacent to the cylindrical outer end portion thereof in which the second tubular connector member is inserted. The retainer comprises a cylindrical base portion adapted to fit in the cylindrical outer end portion of the first tubular connector member and a plurality of pawls extending from the cylindrical base portion for resiliently engaging in the annular groove of the second tubular connector member. Each of the pawls has a portion insertable in the apertures of the first tubular connector member to axially retain the retainer in the first tubular connector member and a free end portion extending radially inward to engage in the annular groove of the second tubular connector member.
Therefore, it is possible to provide either an annular projection on the second tubular connector member, as described in U.S. Pat. Nos. 4,524,995 and 4,601,497, or an annular groove, as described in Japanese Publication No. 63-17390 to cooperate with the resilient retainer. Such an annular projection or an annular groove should have a blocking wall disposed transversely to a central axis of the second tubular connector member, as particularly referred to in U.S. Pat. No. 4,524,995. Namely, at least one of the side walls of the annular projection or the annular groove must be formed perpendicular to the central axis of the second tubular connector member to axially abut against the inner edges of the retainer. In this way, the height of the annular projection or the depth of the annular groove should be sufficient to ensure that the inner edges of the retainer does not slip over the annular projection or the annular groove. The problem that arises in this aspect is that, if the second tubular connector member is made of a thin walled pipe, it is difficult to form an annular projection having an enlarged height or an annular groove having an enlarged depth on the thin walled second tubular connector member and integrally therewith.
Further, in its original shape, the retainer is shaped such that the distance between the opposing pawls or jaws is smaller than the outer diameter of the second tubular connector member, so that it can resiliently engage with the second tubular connector member. Thus the inner edges of the retainer normally are strongly forced against the second tubular connector member, biting into the outer surface of the second tubular connector member and disturbing the rotatability of the second tubular connector member relative to the first tubular connector member.